This invention relates to a shaft-type countercurrent heat exchanger for the heat treatment of finegrained material with hot gas which flows upward through the heat exchanger countercurrent to the material. The heat exchanger comprises several vertically adjacent countercurrent chambers which are separated from one another by funnel-like reductions in the cross-section of the shaft and at least two cyclones connected in parallel at the upper end of the shaft.
A shaft-type countercurrent heat exchanger of the kind mentioned above is known for example from Zement-Kalk-Gips, 1965, page 628 (FIG. 9). It consists of four vertically adjacent countercurrent chambers and of two cyclones connected in parallel in the uppermost stage and is distinguished primarily by its simple construction and compactness.
The object of the present invention is to develop further the known countercurrent heat exchanger to the extent that its efficiency level, i.e., the transfer of heat from the hot gas to the fine-grained material, is improved.